Head drum assembly mounting structure on a deck of a tape recorder

ABSTRACT

In a head drum assembly mounting structure on a deck of a tape recorder, a plurality of connecting holes and positioning holes are formed in a drum boss provided at a lower portion of a fixing drum, and a plurality of coupling holes and positioning pins are formed in a drum base which is slant disposed on a main base. By using the positioning holes and the positioning pins as positioning means which are connected to each other in complementary fashion, the coupling holes of the drum base and the connecting holes of the drum boss are aligned with each other, and by fastening a screw into such aligned coupling holes and the connecting holes, the head drum assembly can be directly coupled to the main base while being slant disposed with respect to the main base. Accordingly, any possible damage to a lead line is prevented, and assembly efficiency is improved, while the number of parts and the manufacturing cost are reduced.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Ser. No. 09/767,865 filed in theU.S. Patent and Trademark Office on 24 Jan. 2001 now U.S. Pat. No.6,724,579, and assigned to the assignee of the present invention.

CLAIM OF PRIORITY

This application makes reference to, incorporates the same herein, andclaims all benefits accruing under 35 U.S.C. §119 and §120 from myapplication entitled HEAD DRUM ASSEMBLY OF A VCR filed with the KoreanIndustrial Property Office on 24 January 2000 and there duly assignedSer. No. 2000/3254, and my application entitled HEAD DRUM ASSEMBLYMOUNTING STRUCTURE ON A DECK BASE OF A TAPE RECORDER filed with theKorean Industrial Property Office on 14 October 2000 and there dulyassigned Ser. No. 2000/60519.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a head drum assembly, and moreparticularly to a head drum assembly mounting structure on a deck of atape recorder.

2. Description of the Background Art

Generally, a tape recorder such as a camcorder, VCR, or the like has afast rotating head drum assembly mounted on a main base of a deck. Thehead drum assembly includes a magnetic head which scans a travelingmagnetic tape for information recording/reproducing.

As shown in FIG. 1, a conventional head drum assembly 20 includes anupper drum 21 and a lower drum 22. The upper drum 21 and lower drum 22are disposed on a same shaft 23 in such a manner that the upper drum 21is rotatably supported by the shaft 23, and the lower drum 22 is fixedto the lower portion of the upper drum 21. The head drum assembly 20,constructed as above, usually employs a Helical scanning type in whichthe head drum assembly 20 is slanted on a predetermined slant withrespect to the main base 10 of the deck to stably guide the running ofthe magnetic tape.

The Helical scanning type head drum assembly 20 includes a guide groove22 a formed on an outer circumference of a lower end of the lower drum22. Ends of a plurality of brackets 24 are inserted into the guidegroove 22 a in such a manner as to be spaced from each other by auniform distance. In this situation, the lower drum 22 and the otherends of the brackets 24 are mounted on the drum base 11 of the main base10. The other ends of the brackets 24 are fastened to the drum base 11by screws (S). A reference numeral 22 b refers to a lead line, which isan outer circumference of the lower drum 22 stepped to guide thetraveling of the magnetic tape. Also, reference numeral 25 is a drumboss received in a central opening of the drum base 11, and S1 refers tocoupling holes formed in the brackets 24.

As shown in FIG. 2, the drum base 11 is a ring type rib, for example,having an opening formed in the center thereof, three screw couplingholes S2 formed therein at a uniform distance from each other, and apair of positioning pins 11 a and 11 b.

FIG. 3 is a sectional view taken on line III—III of FIG. 2. The drumbase 11 is usually integrally formed with the main base 10 by properprocesses such as a drawing, or the like, on a predetermined slant withrespect to the main base 10.

The pair of positioning pins 11 a and 11 b stand substantially in aperpendicular relation with the slant plane of the drum base 11. Thepositioning pins 11 a and 11 b determine the mounting position andposture of the lower drum 22 which is mounted on the drum base 11, by acomplementary connection with a positioning hole (not shown) formed in alower surface of the drum boss 25. Accordingly, screw coupling holes (S1and S2) of the drum base 11 and the brackets 24 are aligned with eachother, permitting the screw (S) to pass therethrough and fasten.

In the conventional head drum assembly mounting structure, however, dueto the fact that the brackets 24 press the lead line 22 b while the drumbase 11 and the brackets 24 are fastened by the screws (S), the leadline 22 b of the lower drum 22 is often deformed.

Further, in order to insert one end of each of the brackets 24 into thelower drum 22, many processes are required, such as a process ofprocessing the guide groove 22 a for receiving the ends of the brackets24, and also many parts are required, such as three brackets 24, thescrew (S) and the pair of positioning pins 11 a and 11 b, or the like.Accordingly, due to deteriorated assembly efficiency and increasedmanufacturing cost, productivity is deteriorated.

SUMMARY OF THE INVENTION

The present invention has been developed to overcome the above-mentionedproblems of the related art, and accordingly, it is an object of thepresent invention to provide a head drum assembly mounting structure ona deck base of a tape recorder capable of accomplishing costeffectiveness by decreasing the number of parts and improving assemblyefficiency, and also establishing a quality stabilization by basicallypreventing any damage to the lead line of the lower drum during theassembly process.

The above object is accomplished by a head drum assembly mountingstructure on a deck base of a tape recorder according to the presentinvention, including a head drum assembly which comprises: an upperdrum, a lower drum, and a drum boss, all of which are connected to thesame shaft; a drum base slanted on a main base of a deck; and apositioning and connecting means for determining a relative position ofthe drum base and the drum boss while complementarily connecting thedrum base with the drum boss.

The positioning and connecting means includes: at least one positioninghole and at least one first coupling hole formed in a lower portion ofthe drum boss; a positioning pin formed on the drum base so as to beinserted into the positioning hole; and a second coupling hole formed inthe drum base and corresponding to the first coupling hole for receivinga coupling member.

According to another aspect of the present invention, the positioningand connecting means comprise: at least one locking hole formed in alower portion of the drum boss; and a hook pin formed on the drum baseand corresponding to the locking hole for being complementarilyconnected with the locking hole.

The above object is also accomplished by a head drum assembly mountingstructure on a deck base of a tape recorder according to anotherembodiment of the present invention, and including: a head drum assemblyincluding an upper drum and a lower drum, both of which are connected tothe same shaft; a slant boss formed on a lower portion of the lower drumfor supporting the head drum assembly so as to be slanted with respectto a main base of a deck for surface-contact between the head drumassembly and the main base of the deck; and a connecting means forconnecting the main base and the slant boss.

According to another aspect of the present invention, a positioningmeans is provided for determining a connecting position of the head drumassembly by a complementary connection between the main base and thelower drum. The positioning means includes: a plurality of positioningholes formed in the main base; and a plurality of guiding bossesprotruding from a lower portion of the lower drum by different lengths,and corresponding to the plurality of positioning holes, so as to beinserted into and supported in the plurality of positioning holes.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings in which likereference symbols indicate the same or similar components, wherein:

FIG. 1 is a schematic sectional view showing a head drum assemblymounting structure of a conventional tape recorder;

FIG. 2 is a schematic plan view showing a drum base of FIG. 1;

FIG. 3 is a schematic sectional view taken on line III—III of FIG. 2;

FIG. 4 is a schematic sectional view showing a head drum assemblymounting structure of a tape recorder according to a first preferredembodiment of the present invention;

FIG. 5 is a schematic plan view showing a drum base of FIG. 4;

FIG. 6 is a schematic plan view taken on line VI—VI of FIG. 5;

FIG. 7 is a sectional view showing a modified example of the mainportion of the present invention;

FIG. 8 is a schematic sectional view showing the head drum assemblymounting structure of a tape recorder according to a second preferredembodiment of the present invention;

FIGS. 9 and 10 are, respectively, a bottom view and a perspective viewof the lower drum of FIG. 8; and

FIG. 11 is a schematic side elevation for explaining a modified exampleof the main portion of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in greater detail withreference to the accompanying drawings.

As shown in FIGS. 4 through 6, in the head drum assembly mountingstructure of a tape recorder according to the first preferred embodimentof the present invention, a drum boss 230 integrally formed with a lowerportion of a lower drum 220 of a head drum assembly 200 is mounted on adrum base 110 and fastened by a screw. Here, the drum base 110 isintegrally formed with a main base 100 while being slanted with respectto the main base 100.

The main aspect of the present invention is a positioning and connectingmeans, which is provided to position and connect the drum base 110 andthe drum boss 230, for determining a relative connecting position of thedrum base 110 and the drum boss 230 by a complementary connection.

The positioning and connecting means includes two or three first screwholes 231 formed in a lower portion of the drum boss 230, onepositioning hole 235, two or three second screw holes S3 penetrated intothe drum base 110 and corresponding to the first screw holes 231 forpermitting the screws (S) to pass therethrough, and a positioning pin111 formed on the drum base 110 and corresponding to the positioninghole 235. Throughout the description of the present invention, likeelements are designated by the same reference numerals.

Meanwhile, according to another aspect of the present invention, an endof the shaft 240 protruding downward from the drum boss 230 also servesthe function of the positioning and connecting means through cooperationwith a shaft hole 112 (see FIG. 5) formed in the drum base 110. Morespecifically, when the drum boss 230 of the head drum assembly 200 ismounted on the drum base 110, the insertion of the lower end of theshaft 240 into the shaft hole 112 of the drum base 110 determines aninitial connecting position.

When the drum boss 230 of the head drum assembly 200 is mounted on thedrum base 110, in addition to the insertion of the lower end of theshaft 240 into the shaft hole 112 of the drum base 110, the positioningpin 111 is also inserted into the positioning hole 235, and accordingly,the first screw holes 231 and the second screw holes S3 are aligned witheach other, permitting the screws (S) to pass therethrough and fasten.In order to accomplish such fastening of the screws (S), the relativepositions of the positioning hole 235, the first screw holes 231, andthe second screw holes S3 are determined in advance during processing.

Accordingly, by upwardly inserting, i.e., fastening the screw (s), intothe first screw holes 231 formed on the lower portion of the drum base110, the head drum assembly 200 is directly mounted on the drum base 110of the main base 100.

FIG. 7 shows the positioning and connecting means of another preferredembodiment of the present invention. The positioning and connectingmeans includes at least one locking hole 235′ formed in a lower portionof the drum boss 230, and a hook pin 115 formed on the drum base 110corresponding to the locking hole 235′ for a complementary connectionwith the locking hole 235′.

The hook pin 115 includes a pair of locking ends 115 a and 115 bbranched from a leading end of the hook pin 115 and elastically biasedin opposite directions, and a locking portion 235 a extending from aninner circumference of the locking hole 235′ so as to be locked with thepair of locking ends 115 a and 115 b.

When the hook pin 115 is inserted into the locking hole 235′, thelocking ends 115 a and 115 b of the hook pin 115 are pressed by theinner circumference of the locking hole 235′ and advanced toward thelocking portion 235 a of the locking hole 235′ until the locking ends115 a and 115 b are biased outward and locked in the locking hole 235′.

As described, since the hook pin 115 can serve both as a positioning pinand as a screw, the initial connecting position of the drum boss 230 andthe drum base 110 is determined, while the connection is made by onestep during the connection of the drum boss 230 and the drum base 110.

Meanwhile, although the embodiments of the present invention depict thescrews (S) and the screw holes S3 and 231, or the hook pin 115 and thelockinghole 235′, as the connecting means for connecting the drum boss230 and the drum base 110, it should be noted that other proper typescan also be applied without limitation.

Further, the position of the screws and the screw holes, and of the hookpin and the locking hole, are interchangeable. That is, the screws canbe formed on a lower portion of the drum boss 230, while thecorresponding screw holes are formed in the drum base 110. Likewise, thehook pin also can be formed on a lower portion of the drum boss 230,while the corresponding locking hole is formed in the drum base 110.

FIGS. 8 through 10 show a mounting structure of the head drum assemblyaccording to a second preferred embodiment of the present invention.Throughout the description, like elements will be designated by the samereference numerals.

Referring to FIGS. 8 through 10, in the head drum assembly mountingstructure according to the second preferred embodiment, a slant boss 250integrally formed with a lower portion of the lower drum 220 is coupledwith the main base 100′ by surface-contact. Accordingly, the head drumassembly 200′ is slant-supported on the main base 100′.

The main base 100′ and the slant boss 250 include a plurality ofconnecting holes S3 and 251, respectively, corresponding to each other.By fastening screws (S) into the connecting holes S3 and 251, the mainbase 100′ and the slant boss 250 are coupled to each other.

A positioning means is provided for the main base 100′ and the lowerdrum 220 so as to determine the mounting position of the head drumassembly 200′ through a complementary connection.

It is preferable that the positioning means include a plurality ofpositioning holes S4 formed in the main base 100′, and a plurality ofguiding bosses 261 and 262 protruding from a lower portion of the lowerdrum 220 by different lengths for insertion into the positioning holesS4.

The guiding bosses 261 and 262 support the head drum assembly 200′ onthe main base 100′ in a bridge pattern, while maintaining apredetermined slant of the head drum assembly 200′ with respect to themain base 100′. As shown in FIGS. 9 and 10, different lengths of theguiding bosses 261 and 262 correspond to the varying length of the slantboss 250. The guiding bosses 261 and 262 includes positioning pins 261 aand 262 a protruding from the ends thereof. The positioning pins 261 aand 262 a serve as the positioning means by being inserted into theplurality of corresponding positioning holes (S4) formed in the mainbase 100′.

According to the above embodiment, the head drum assembly 200′ ismounted on the main base 100′ in such a state that the positioning pins261 a and 262 a formed on the ends of the guiding bosses 261 and 262 arealigned with the positioning holes (S4) of the main base 100′. Here, theplurality of connecting holes S3 and 251 formed on the main base 100′and the slant boss 250 are also aligned with each other. In thissituation, the screws (S) are fastened into the plurality of connectingholes S3 and 251 upwardly from the lower portion of the main base 100′,and accordingly, the head drum assembly 200′ is completely mounted.

According to another aspect of the present invention, the screws (S) canalso be fastened into the plurality of connecting holes S3 and 251 insuch a state that the head drum assembly 200′ is turned upside down on ajig and the main base 100′ is also turned upside down. Accordingly, thehead drum assembly 200′ mounting process becomes easier and simpler.

As described above, according to the head drum assembly mountingstructure of the present invention, since the slant boss 250 is coupledto the main base 100′ by screws (S) which are upwardly coupled from thelower portion of the main base 100′, any possible damage to the leadline can be basically prevented.

FIG. 11 shows a modified example of the positioning means fordetermining the mounting position of the head drum assembly 200′.According to this embodiment, additional positioning guides 271 and 272are provided around the guiding bosses 261 and 262.

The positioning pins 271 a and 272 a on the ends of the positioningguides 271 and 272 are connected in the connecting holes (S3) of themain base 100′ (FIG. 8). Here, the guiding bosses 261 and 262 includehemispheric protrusions 261 b and 262 b protruding from ends thereof.Accordingly, the guiding bosses 261 and 262 are supported on the mainbase 100′ in such a manner that the hemispheric protrusions 261 b and262 b are in contact with the main base 100′. As described, since theguiding bosses 261 and 262 are supported on the main base 100′ by thepoint-contact of the hemispheric protrusions 261 b and 262 b with themain base 100′, the contact area is decreased, and the influence of theevenness of the contact area is minimized. As a result, the head drumassembly can be stably assembled.

As described, according to the head drum assembly mounting structure ofthe tape recorder of the present invention, by means of the positioningmeans, the process of assembling the main base with the head drumassembly becomes simpler, and the productivity is increased. Further, byomission of parts such as screws, supporting brackets, or the like, themanufacturing cost can be reduced. Further, since the damage ordeformation of the lead line can be prevented by the improved structure,reliable quality can be accomplished.

1. A main base for use in mounting a head drum assembly on a deck of atape recorder, said main base comprising: a central portion; and anouter portion surrounding said central portion; wherein said centralportion is connected on one side to said outer portion by a downwardlyslanted portion of said central portion, and said central portion isconnected on another side to said outer portion by an upwardly slantedportion of said central portion, whereby said central portion isoriented at an angle with respect to said outer portion; said main basefurther comprising a positioning pin extending upward from said upwardlyslanted portion of said central portion for insertion into a positioninghole formed in the lower portion of the head drum assembly; wherein saidpositioning pin comprises a hook pin which includes at least two lockingends extending upward from said central portion for insertion into thepositioning hole formed in the lower portion of the head drum assembly.2. The main base of claim 1, wherein said central portion is formed withsaid outer portion into one piece.
 3. The main base of claim 1, whereinsaid two locking ends are flexible toward and away from each other so asto move toward each other when initially passing through a narrowportion of the locking hole, and so as to move away from each otherafter entering a wider, locking portion of the positioning hole.
 4. Themain base of claim 1, wherein said central portion is discontinuous soas to have a hole disposed therein for receiving a protrusion extendingfrom a lower portion of the head drum assembly, and wherein said centralportion is discontinuous so as to have at least two screw holes formedtherein for receiving respective screws which pass through said screwholes and are screwed into the lower portion of the head drum assembly.5. A main base for use in a head drum assembly mounting structure on adeck of a tape recorder, said main base comprising: a central portion;and an outer portion surrounding said central portion; wherein saidcentral portion is connected on one side to said outer portion by adownwardly slanted portion of said central portion, and said centralportion is connected on another side to said outer portion by anupwardly slanted portion of said central portion, whereby said centralportion is oriented at an angle with respect to said outer portion; saidmain base further comprising a hook pin which includes at least twolocking ends extending upward from said upwardly slanted portion of saidcentral portion for insertion into the positioning hole formed in thelower portion of the head drum assembly.
 6. The main base of claim 5,wherein said two locking ends are flexible toward and away from eachother so as to move toward each other when initially passing through anarrow portion of the positioning hole, and so as to move away from eachother after entering a wider, locking portion of the positioning hole.7. A main base for use in a head drum assembly mounting structure on adeck of a tape recorder, said main base comprising: a central portion;an outer portion surrounding said central portion; and positioning meansextending upward from said central portion for insertion into apositioning hole formed in a lower portion of the head drum assembly soas to position said main base relative to the head drum assembly;wherein said positioning means comprises a hook pin which includes atleast two locking ends extending upward from said central portion forinsertion into the positioning hole formed in the lower portion of thehead drum assembly.
 8. The main base of claim 7, wherein said twolocking ends are flexible toward and away from each other so as to movetoward each other when initially passing through a narrow portion of thepositioning hole, and so as to move away from each other after enteringa wider, locking portion of the positioning hole.